For companies that invest in side project initiatives, the outcomes can be incredible: Gmail, Google Maps, Twitter, Slack, and Groupon all started as side projects.

My company is young, and our resources are not limitless. So while we aren't yet able to give our team members the green light on the 20 percent rule, we have tried alternatives such as hackathons, side projects, and business case study competitions. Here are the three most important lessons I've learned:

1. You should encourage employee choice and strengths.

As part of our annual all-company retreat, we wanted to do something that would bring team members from different departments together. Our very creative engineering team had heard of hackathons and so we broke up the company into four groups and gave them a full week to come up with an idea, work on it, and present a finished product to the entire company. The winners would get cash prizes and bragging rights for a year.

What went well: The creativity and the camaraderie built among teams. There were some hilarious team names and one team created the framework for what would become our extensive and proprietary dataset.

What we learned: Not all job functions were required to help the team and not everyone performs well in high-stress, competitive, group activity environments. There were team members that were completely left out due to the highly technical nature of their group's project and some folks that simply hated the competitive nature of the event.

Our best version of side projects was when we made it a collaborative instead of a competitive experience and let employees choose which idea to work on. People are most engaged and do their best when they get to work on things that interest them.

2. Ideas require intentional effort and oversight to become solutions.

Our first three iterations of side projects were ideas that had been created by employees and worked on by teams without leaders. The end result, while fantastic ideas, were often not aligned with our business objectives.

We've found having assigned business leaders to give teams their prompts and objectives works well. Everyone plays their best when they know the rules of the game and have a coach to show them how to win.

This year, we gave a team the objective of creating employee resource groups at our company. We assigned an executive sponsor and a team leader. After just a few hours, the team gave an awesome presentation, started our first ERG -- complete with leaders and members -- and created a process for how to start one in the future.

3. Cross-department collaboration fosters trust and innovation.

In every iteration, our team has named side projects as one of the best things our company does each year. They tell us they love getting to know colleagues from other departments and learning about what they do and how they do it. Everyone finds common ground and feels closer as a company after side projects.

Because the teams are intentionally cross-functional, we end up with ideas that never would have come about in a typical workday environment, like a completely new and automated way to connect with our customers. Some of these ideas have become game-changers for our product, our service, and our team -- directly impacting our bottom line.

You don't have to have Google's resources to implement side projects. In January of this year we devoted about eight company hours to side projects, and we've already seen the benefits of the solutions and camaraderie that came out of it.